Add support for --incompatible_config_setting_private_default_visibility

bazelbuild/bazel#12933 indicates this is an older flag, from 2021. But I ran into this with `bazelisk --migrate` (https://github.com/bazelbuild/bazelisk#--migrate) and thought it'd be nice to support it.

PiperOrigin-RevId: 712990438
Change-Id: Ie0282401b44d505e2e34117b1d1dc22aa3380c02

.bazelrc

@@ -18,6 +18,11 @@ build --cxxopt='-std=c++17'
 # https://github.com/bazelbuild/bazel/pull/15327 for details.
 build --incompatible_disallow_empty_glob
 
+# Flip incompatible_config_setting_private_default_visibility to avoid breaking
+# forward compatibility. See https://github.com/bazelbuild/bazel/issues/12933
+# for details.
+common --incompatible_config_setting_private_default_visibility
+
 # Link Google Test against Abseil and RE2.
 build --define='absl=1'
 

tcmalloc/BUILD

@@ -32,6 +32,7 @@ config_setting(
     flag_values = {
         "@bazel_tools//tools/cpp:compiler": "clang",
     },
+    visibility = ["//tcmalloc:__subpackages__"],
 )
 
 cc_library(